What is a trainer? A trainer is a program written to intercept and alter the memory addresses of games that are running in the background. Usually trainers contain such features as GOD MODE, UNLIMITED LIVES and others. Since trainers address specific memory locations, they are usually written to only support a specific version of a game.

Crime Life: Gang Wars

When fighting Justiss, you must throw him into the flames that come
out of the pipes on the wall. Just trying to beat him down will not
work, as he will not lose health at all. Punch and kick him a few
times, then throw him towards the flame valves. Make sure to throw
him towards one that is not lit. Throw him towards the one that is
beside a lit one. Now, punch and kick him to keep him close to the
wall. The flames will come on. Run the other way as fast as
possible. Keep punching and kicking him to build up your special
while you are trying to put him to the wall. Do not perform any
specials just yet. Once it goes into the next intermission sequence,
the flames get turned off and he starts losing health when you hit
him. When the intermission sequence is playing, he calls in some
backup (about 3 or 4 men). Ignore them. When the intermission
sequence is done, run directly for Justiss and do a Heavy special.
This will bring his health down a lot. If you only end up doing a
Brutal and use 2 special bars, beat down the backup. Fatal them so
that you get health from them, then do another big attack on
Justiss. By now he should be into the Fatal stage. Run up, execute a
fatal attack, and just protect yourself from the backup until the
intermission sequence begins. You will then be King Pin.

Break pay phones and parking meters for free money. You can get $10
from pay phones and $3 from parking meters.

Go to Bringley Hill. Go to any store start the robbery. Punch the
men but do not kill them, Do not let them say "help". When you get
$1,000, take the bag into the robbery car. If you have a lot of
stars (three), go back to the Outlaws crib. Enter it then go out and
there will be no stars.